The present invention relates to novel pigment colourants, to their preparation and to their use in the mass-colouring of synthetic materials.
Pigment colourants and their use in the mass-colouring of synthetic materials are known. It has been found, however, that such colourants do not always fully meet the highest demands, especially in respect of fastness to light, thermostability and/or colour strength. Accordingly, there is a need for new pigment colourants which yield coloured materials that are fast to light, thermostable and of good tinctorial strength, and which exhibit good all-round properties.
Surprisingly, it has now been found that the pigment colourants according to the invention meet the above-mentioned criteria to a considerable degree.
Accordingly, the present invention relates to pigment colourants of formula 
wherein
R1 is C1-C6alkyl, C1-C6alkoxy, phenoxy or halogen,
R2 is hydrogen, C1-C6alkyl, C1-C6alkoxy, phenoxy, halogen, acylamino, xe2x80x94CH2NHacyl or the radical 
xe2x80x83and
R3 is C1-C6alkyl, C1-C6alkoxy, phenoxy or halogen,
the ring A may be further substituted by xe2x80x94SO3xe2x88x92M+, wherein M+ is a cation, and the rings B and C may be unsubstituted or further mono- or poly-substituted by halogen, hydroxy, xe2x80x94SH, amino, C1-C6alkylamino, C1-C6alkyl, C1-C6alkoxy, phenoxy, acylamino, C1-C6thioalkyl or by thiophenyl, and the ring B may be substituted in the 5- or 8-position by a radical of formula 
wherein R1, R2 and R3 are as defined above.
R1, R2 and R3 as C1-C6alkyl are, for example, methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, amyl, tert-amyl (1,1-dimethylpropyl), 1,1,3,3-tetramethylbutyl, hexyl, 1-methylpentyl, neopentyl, cyclopentyl, cyclohexyl, as well as the associated isomers.
R1, R2 and R3 as C1-C4alkoxy are, for example, methoxy, ethoxy, propoxy or butoxy.
R1, R2 and R3 as halogen are, for example, chlorine, bromine or iodine, and preferably chlorine.
Acyl in acylamino or in the formula xe2x80x94CH2NHacyl is preferably formyl, acetyl, chloroacetyl, acryl or propionyl.
C1-C6Thioalkyl as a substituent of ring B and/or C is, for example, methylthio, ethylthio, propylthio or butylthio.
R1 is preferably ethyl or bromine, and especially methyl.
R2 is preferably hydrogen, ethyl, phenoxy, and especially methyl.
R3 is preferably ethyl or bromine, and especially methyl.
The cation M+ is, for example, Na+, Li+, K+, Ca2+, Mg2+, Sr2+, Al3+ or the cation of an organic amine such as, for example, ethylenediamine, diethylenetriamine, triethanolamine, tri-isopropanolamine, cyclohexylamine, hexamethylenediamine, Rosin Amine D and Primene 81R.
Preference is given to pigment colourants of formula (1) wherein the ring B is substituted by chlorine, and special preference is given to those wherein the ring B is unsubstituted or is substituted in the 5- or 8-position by a radical of formula 
wherein R1,
R2 and R3 have the definitions and preferred meanings mentioned above.
Also preferred are pigment colourants of formula (1) wherein the ring C is unsubstituted or is substituted by bromine.
Special preference is given to the pigment colourants of formula (1) wherein the ring B is unsubstituted or is substituted in the 5- or 8-position by a radical of formula 
wherein R1, R2 and R3 are methyl, and the ring C is unsubstituted.
Very special preference is given to pigment colourants of formula (1) wherein the ring B is unsubstituted or is substituted in the 5-position by a radical of formula 
wherein R1, R2 and R3 are methyl, and the ring C is unsubstituted.
The pigment colourants of formula (1) according to the invention are prepared, for example, by reacting 1-chloro-, 1-nitro- or 1-sulfo-anthraquinone with one equivalent of a compound of formula 
wherein R1, R2 and R3 are as defined for formula (1), in the presence of alkali acetate, copper and/or a copper salt and optionally in an organic solvent, or by reacting 1,5- or 1,8-dichloro-, 1,5- or 1,8-dinitro- or 1,5- or 1,8-disulfo-anthraquinone with two equivalents of a compound of formula (2a) in the presence of alkali acetate, copper and/or a copper salt and optionally in an organic solvent, and, where appropriate, introducing further substituents into the resulting compound according to conventional methods.
The compounds of formula (2a) are known or can be prepared according to known methods.
The present invention relates also to a method of preparing coloured plastics or polymeric coloured particles, which method comprises mixing together a high molecular weight organic material and at least one pigment colourant of formula (1) in an amount having a colouring effect.
Colouring of high molecular weight organic substances with the pigment colourant of formula (1) is carried out, for example, by mixing such a pigment colourant with the substrates using rolling mills, mixing or grinding apparatuses, as a result of which the pigment colourant is dissolved or finely divided in the high molecular weight material. The high molecular weight material with the admixed pigment colourant is subsequently processed by methods known per se, for example calendering, compression moulding, extrusion, coating, spinning, casting or by injection moulding, whereby the coloured material acquires its final form. The admixture of the pigment colourant may also be carried out immediately prior to the actual processing step, for example by continuously feeding a solid pigment colourant, for example a pulverulent pigment colourant, and, at the same time, a granulated or powdered high molecular weight organic material, and optionally also additional ingredients, for example additives, directly into the intake zone of an extruder, where mixing takes place immediately before processing. In general, however, it is preferred to mix the pigment colourant with the high molecular weight organic material beforehand, since more uniformly coloured substrates can be obtained.
In order to produce mouldings that are not rigid or to reduce their brittleness, it is often desirable to incorporate so-called plasticisers into the high molecular weight compounds prior to shaping. There may be used as plasticisers, for example, esters of phosphoric acid, phthalic acid or sebacic acid. In the method according-to the invention, the plasticisers may be incorporated into the polymers before or after the. incorporation of the colourant. It is also possible, in order to achieve different colour shades, to add to the high molecular weight organic substances, in addition to the pigment colourant of formula (1), also further pigments or other colourants in any desired amounts, optionally together with further additional ingredients, for example fillers or siccatives.
Preference is given to the colouring of thermoplastic plastics especially in the form of fibres. Preferred high molecular weight organic materials that can be coloured according to the invention are, very generally, polymers having a dielectric constant xe2x89xa72.5, especially polyester, polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), polyamide, polyethylene, polypropylene, styrene/acrylonitrile (SAN) or acrylonitrilelbutadiene/styrene (ABS). Special preference is given to polyester and polyamide. Very special preference is given to linear aromatic polyesters, which can be obtained by polycondensation of terephthalic acid and glycols, especially ethylene glycol, or condensation products of terephthalic acid and 1,4-bis(hydroxymethyl)cyclohexane, for example polyethylene terephthalate (PET) or polybutylene terephthalate (PBTP); also polycarbonates, for example those of xcex1,xcex1-dimethyl4,4-dihydroxy-diphenylmethane and phosgene, or polymers based on polyvinyl chloride and on polyamide, for example polyamide 6 or polyamide 6.6.
The pigment colourants according to the invention impart to the above-mentioned materials, especially to the polyester and polyamide materials, tinctorially strong, level colour shades which have very good fastness properties in use, especially good fastness to light and good thermostability.
The Examples which follow serve to illustrate the invention. In the Examples, unless indicated to the contrary, parts are parts by weight and percentages are percentages by weight.
Temperatures are given in degrees Celsius. The relationship between parts by weight and parts by volume is the same as that between grams and cubic centimetres.